The Conservation Commission this month endorsed proposed regulations that would ban importing white-tailed deer, mule deer and their hybrids from other states and require double-fencing for new permit-holders. The rules also would mandate testing of deer at least 6 months old that die and require retaining records for 15 years.

Supporters contend the changes are needed to combat chronic wasting disease and reduce the risk of it spreading. The disease is deadly to deer, elk and other cervids and can be transmitted through contact among animals and indirectly through soil and other substances.

Chronic wasting disease has been identified in 23 states and two Canadian provinces, and Missouri conservation officials say there have been 11 confirmed cases of chronic wasting disease in captive deer within the state since 2010 and 10 cases in wild deer.

Missouri's deer industry objects to the proposals, saying many of the rules unnecessarily go too far and would threaten their businesses. A 30-day public comment period about the regulations starts July 16.

Lawmakers entered the fray this spring, approving measures that would define captive deer as livestock. That would give the Department of Agriculture responsibility for overseeing the industry, make ranchers eligible for a sales tax exemption and potentially open a market for the venison. The legislation is pending before Nixon.

Sam James, president of the Missouri Deer Association, said the industry wants regulation. He said facilities currently are overseen by both the state Agriculture and Conservation departments but that it seems conservation officials have targeted breeders and hunting preserves. The deer association worked to pass legislation defining captive deer as livestock.

"We cannot survive as an industry under the Department of Conservation, and so we decided this is our only way to go or die a slow death," said James, who manages two hunting preserves and a breeding facility in central Missouri.

The Conservation Department is governed by a four-member commission composed of gubernatorial appointees.

Conservation Director Robert Ziehmer said Missourians voted to make the agency responsible for wildlife and that it has a long track record of managing captive and free-ranging animals such as bear, timber rattlesnakes and coyotes. Ziehmer said the agency is watching to see what happens with the legislation.

"Our intent, our view, is that we will continue to move forward and regulate white-tailed deer in the state, regardless of whether it's free-ranging or captive," he said.

Deer are big business in Missouri. Conservation officials estimate hunting supports $1 billion of economic activity and report nearly 252,000 deer were killed during the 2013 hunting season. The captive deer industry could account for $133 million of economic activity with 200-250 breeders and several dozen hunting ranches.